| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 38.4 | 131 |
| 2015 | 38 | 157 |
| 2014 | 38.9 | 155 |
| 2013 | 38 | 160 |
| 2012 | 36.6 | 160 |
| 2011 | 33.5 | 162 |
| 2010 | 28.9 | 161 |
| 2009 | 25.4 | 162 |
| 2008 | 25.6 | 162 |
| 2007 | 22 | 162 |
| 2006 | 18.6 | 161 |
| 2005 | 11.1 | 169 |
| 2004 | 8.6 | 173 |
| 2003 | 8.2 | 169 |
| 2002 | 8.1 | 168 |
| 2001 | 8.1 | 163 |
| 2000 | 8.2 | 163 |
| 1999 | 7.5 | 163 |
| 1998 | 8 | 159 |
| 1997 | 8.2 | 159 |
| 1996 | 7.5 | 159 |
| 1995 | 6.9 | 158 |
| 1994 | 6.1 | 154 |
| 1993 | 5.3 | 151 |
| 1992 | 4.6 | 150 |
| 1991 | 4.1 | 149 |
| 1990 | 4.6 | 141 |
| 1989 | 4.1 | 125 |
| 1988 | 4.3 | 117 |
| 1987 | 3.9 | 119 |
| 1986 | 5.4 | 117 |